Objective: To explore the characteristics of clinicopathology and diagnostic criteria of ovarian juvenile granulosa cell tumor. Methods: The clinical data, histopathologic observation and immunohistochemical staining were studied in two cases of juvenile granulosa cell tumor. Results: Microscopic examination showed two cases of tumor was composed of ovoid cells or fusiform cells with cytoplasmic light dye, part of vacuolated with a nest. The multiple nodular growth and myxoid background with the surrounding ovary tissues which had a clear boundary were present. Blood vessels were rich with part of the cell growth. Mitosis often appears (5~7/HPF), nuclear groove was not obvious, and it did not see Call-Exner corpuscle. Immunohistochemically, revealed positivity for ER, PR, Vimentin and α-inhibit, and Ki-67 index ranges from 25% to 40%. Conclusion: Ovarian juvenile granulosa cell tumor is a rare tumor, and is easily confused with other tumor, leading to misdiagnosis. Clinicians should pay more attention on its clinicopathological characteristics.